Re: [PATCH v2] parport_pc: Also enable driver for PCI systems

[Maciej W. Rozycki]

On Wed, 2 Mar 2022, Icenowy Zheng wrote:

> > The only PCI platforms that actually can't make use of PC-style
> > parallel 
> > port hardware are those newer PCIe systems that have no support for
> > I/O 
> > cycles in the host bridge, required by such parallel ports.  Notably,
> > this includes the s390 arch, which has port I/O accessors that cause 
> > compilation warnings (promoted to errors with `-Werror'), and there
> > are 
> > other cases such as the POWER9 PHB4 device, though this one has
> > variable 
> > port I/O accessors that depend on the particular system.  Also it is
> > not 
> > clear whether the serial port side of devices enabled by
> > PARPORT_SERIAL 
> > uses port I/O or MMIO.  Finally Super I/O solutions are always either
> > ISA or platform devices.
> 
> Just spot this patch in linux-riscv mailing list, I think there's a
> pending patchset that tries to add a HAS_IOPORT Kconfig option, which
> can be used in this situation.

 Thanks for your input.

 That has been actually discussed already with a conclusion that more work 
is required to have HAS_IOPORT supported, see the thread starting from: 
<https://lore.kernel.org/lkml/CAMuHMdW-utcFzCZTgqONjxs=U662nF0=aBQu7Zi7FBQouwiA3g@xxxxxxxxxxxxxx/>. 
(there's a reference to the HAS_IOPORT patchset there as well).  Once that 
has been sorted configuration conditions for the parport driver can be 
updated accordingly.  For the time being the !S390 qualification should 
do.

  Maciej